Multibarrel automatic weapon

ABSTRACT

A Gatling type gun having a plurality of barrels fixed in a rotor, and an endless chain of separable chambers passing along a path around said rotor into and out of alignment with said barrels, and means for rigidly controlling the movement of said chambers along said path.

United States Patent Ashley et al.

[54] MULTIBARREL AUTOMATIC WEAPON [72] Inventors: Eugene Ashley,Burlington; Douglas P. Tassie, Williston; James M. Seemann, Burlington,all of Vt.

[73] Assignee: General Electric Company [22 Filed: March 10, 1970 V [21]Appl. No.: 18,099

[52] U.S. Cl. ..89/12, 89/33 MC [51] Int. Cl. ..F41d 7/02 [58] Field ofSearch ..89/12, 13, 126, 155, 33;

[56] References Cited UNITED STATES PA'DENTS 3,041,939 7/1962 Dardick.;..s9/ ss 1,424,751 8/1922 Bangerter ..89/155 X 2,959,106 11/1960O'Brien 2,856,819 10/1958 Meyers et al. ..89/33 MC PrimaryExaminer-Samuel W. Engle Attorney--Bailin L. Kuch, Harry C. Burgess,Irving M. Freedman, Frank L. Neuhauser, Oscar B. Waddell and Joseph B.Forman [5 7] ABSTRACT A Gatling type gun having a plurality of barrelsfixed in a rotor, and an endless chain of separable chambers passingalong a path around said rotor into and out of alignment with saidbarrels, and means for rigidly controlling the movement of said chambersalong said path.

9 Claims, 12 Drawing Figures PA'TENTEDUEB 19 m2 SHEET 1 BF 8 EugeneAshley Douglas P. Tassie James M. Seemann INVENTOR.

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Armewc P A TENT ED 19 I973 3.706, 259

sum 2 OF 8 Eugene Ashley Douglas P. Tassie James M. Seemann I NVEN TOR.

Lay/AZ PATENTED DEC 19 m2 SHEET 3 BF 8 00. NON

Eugene Ashlc Douglas P. Tassic James M. Seemann INVEJYIUR.

PATENTED l 9 I91? 3. 706, 259

saw u ur a 8 8 Eugene Ashley Douglas P. Tassie James M. Seemann I NVENTOR.

P'A'TENTED mac 19 I972 SHEET 5 0F 8 I NVENTOR. Eugene Ashley Doug las P.Tassie s M. Seemann PA'TENTED DEC 19 I972 SHEET 8 BF 8 ugene Ashley DougJam e las P. Tassie S M. Seemann INVENTOR.

MULTIBARREL AUTOMATIC WEAPON BACKGROUND OF THE INVENTION Theinventionhereindescribed was made in the course of or under a contract orsubcontract thereunder with the Department of Defense.

' 9, 1872. This gun had a stationary housing; and a rotor assembly,journaled within the housing, having barrels and 10 reciprocating bolts.The bolts were cammed by the housing and their function was responsiveto the angular rotation of the rotor assembly. The gun fired casedammunition, which was chambered, fired, and ejected by the boltassembly. The first modern version of the Gatling gun is shown in U.S.Pat. No. 2,849,92l issued to Harold McC. Otto on Sept. 2, 1958, and amore recent version is shown in U.S. Pat. No. 3,380,343 issued to RobertE. Chiabrandy et al. on Apr. 30, 1968. Each of these modern guns issimilar to the classic gun in having pluralities of barrels, chambersand bolts to shoot cased ammunition.

In cased ammunition the case serves, inter alia, two functions, viz: itprovides a seal at the aft end of the chamber; and it provides a handleon the round of ammunition for ejection in the event of a misfire.However, the case amounts to some 40 percent of the weight of the round,which if saved, would provide a responsive decrease in system weight, orwould provide that much more ammunition storage capacity.

SUMMARY OF THE INVENTION alignment with said barrels, and means forrigidly controlling the movement of said chambers along said path.

BRIEF DESCRIPTION OF THE DRAWING These and other objects, features andadvantages will be apparent from the following specification thereoftaken in conjunction with the accompanying drawing in which:

FIG. 1 is a perspective view from an aft viewpoint of a weapon embodyingthis invention;

FIG. 2 is a perspective view from a forward viewa point of the weapon ofFIG. 1;

FIG. 3 is a side elevated view, in cross-section, of the weapon of FIG.1;

FIG, 4 is a top plan view of the weapon of FIG. 1; FIG. 5 is an aft endview of the weapon of FIG. 1;

FIG. 6 is an aft end view in cross-section taken along the plane Vl-VIof FIG. 3, particularly illustrating the chain of chambers;

FIG. 7 is a forward end view in cross-section taken along the planeVII-VII of FIG. 3, particularly illustrating the misfire conveyor; and

FIGS. 8 and 9 are detail perspective views of the misfire conveyor,

FIG. 10 is a diagram of FIG. 6 for an eight chamber gun,

FIG. 11 is a diagram of a second embodiment, similar to FIG. 6, for a 10chamber gun, and

FIG. 12 is a broken view of the weapon of FIG. 1.

THE PREFERRED EMBODIMENT The weapon shown in FIG. 1 is a variantof theclassic Gatling principle, and uses a rotating cluster of barrels whichis secured in a rotor assembly and is driven by an external powersource. Conventional, reciprocating bolts are not employed. Instead, aseries of linked tubular firing chambers transport the cartridges intothe rotor. In the firing position each chamber rests in a respectivedeep recess in the rotor and is longitudinally secured or locked betweenthe barrel breech face and a surface of the rotor recess. The chambersare swung out of the rotor recess for loading fresh cartridges, and forejecting such misfires as occur. This is accomplished by using morechambers than barrels, e.g., a loop of eight or more chambers for acluster of six barrels. Since the length of the loop is thus longer thanthe circumference of the pitch circle of the barrel cluster, the loopextends free of the rotor for a portion of its travel and is open forloading and chambering by a stationary cam. The chamber then moveslaterally into lock position and firing can thereupon take place. Thereis no need for a structural locking operation. The fore and aftcomponents of the firing pressure pulse are reacted directly into therotor structure, and the lateral components are contained by hooptension in the wall of the chamber.

The housing assembly 10 includes an aft housing 12 and a forward housing14. The aft housing has a rabbet 16 which receives a lip 18 on thetransverse wall 19 of the forward housing for longitudinal alignment.Radial alignment and clamping are provided by a plurality of mating boltholes and bolts, not shown. A bearing block 20 extends forwardly fromthe wall 19, and together with a rib 21, supports the misfire ejectionassembly 22. A pair of recoil attenuator assemblies 23 are also housedin the forward housing 14. Each recoil attenuator assembly, as best seenin FIG. 4, includes a spindle 24 disposed in a bore 26 through anenlargement in the housing. The forward end of the spindle extends intoa clevis 28 of the gun mount and is retained by a pivot bolt 30. An aftexternal bushing 32 is adjustably threaded into the bore 26, and has ashoulder 34 to retain the aft end of an aft internal bushing 36. Amultielement, friction damped spring 38 is captured between the bushing36 and a forward washer 39 which bears against a shoulder 40 on thespindle, and a shoulder 42 in the housing bore. Compression of thespring is adjusted by a nut 44 bearing against the bushing 36 andthreaded on a stud 46 which is threaded into the aft end of the spindle24.

The feeder assembly is also housed in the aft housing 12. The feederassembly includes a drive shaft 52 which is j-ournaled through bearingblocks 54 and coupled to a knife blade clutch assembly 56. A pair offour toothed sprockets 58' are fixed to the shaft to positively advancerounds, coming down along and between a pair of guides 60, through anopening 62 in the housing. The clutch assembly 56 may be of the typeshown in U.S. patent application Ser. No. 386,656 filed Oct. 1, 1969 byL. K. Wetzel and assigned to a common assignee.

A rotor assembly is journaled for rotation in the housing. The rotorassembly includes a main rotor 72 which has a central, longitudinal bore74 and six longitudinal bores 76 in an annular row. Six gun barrels 78are respectively mounted in the bores 76 and secured to the rotor bysuitable means, not shown, such as interrupted threads. The rotor isjournaled to the forward housing by a pair of annular ball bearingassemblies 80 which is secured by a retaining ring 81. A forward ringgear 82 is captured onto and between the gun barrels and the rotor. Amediate clamp 84 clamps the barrels together and is journaled by a ringbearing 86 to a forward gun mount ring 88. A forward clamp 90 clamps theforward ends of the gun barrels.

The aft portion of the rotor 72 has six recesses 100, each coaxial witha respective gun barrel and having a forward transverse face 102 and anaft transverse face 104. The aft ends 106 of the barrels have respectiveinserts 108 fixed thereto which project slightly aft of the face 102. Aring gear 110 is fixed to and is coaxial with the aft end of the rotor.The gear has a peripheral annulus of centrifugally directed teeth 112,and an aft, longitudinally extending annulus of six cam ramp surfaces114.

A retaining fastener 116 which is used to longitudinally secure the gearto the rotor comprises a formed rectangular wire ring. The ring takes aG shape with the distal ends of both legs turning centrifugally from thecircumference. The ring has a diametral clearance fit around acircumferential groove in the hub of the gear. The legs of the ringprotrude through a slot in the hub so that they can be reached throughthe center hole of the gear. The outside diameter of the ring, when thering is unconstrained, is slightly larger than the outside diameter ofthe hub. When the legs of the ring are squeezed together, accessiblethrough the center hole, the ring contracts to an outside diameter equalto or less than the diameter of the hub. The hub can then be insertedinto the rotor bore 74 which contains a groove to accommodate the ringwhen it is unconstrained. When the hub is assembled and the legs arereleased, the ring is disposed in part in each groove, locking the hublongitudinally.

Six firing pin assemblies 120 are mounted in the aft end of the rotor72. Each assembly is disposed in a respective bore 120 which is coaxialwith a respective gun barrel, and includes a body 124 having a stemportion 126 press fitted into the bore and a head portion 128. The bodyhas a central bore 130 with an internal neck 132. A spindle 134 rides inthe bore 130 and has a forward flange 136 and an aft spool 138. Acompression spring 140 is disposed on the spindle between the bore neck132 and the spindle spool 138 to bias the spindle aft, that is, toretract the firing pin.- A fixed retraction blade 142 is fixed to theaft housing to ensure the retraction of the spool 138, by cammingrearwardly any unretracted spool.

Each of the six firing pins is struck in sequence by a single, springloaded hammer assembly 144. The assembly includes a rod 146 mountedthrough and between two bearing blocks 148 and 150 which extendoutwardly from the aft housing. A support block 152 is fixed at itslower end to the forward end of the rod 146 and at its upper end to oneend of a lateral rod 154 whose other end is adjustably fixed to thehousing, by two nuts 155, whereby to preclude rotation of the rod 146. Ahammer arm 156 pivotally mounted at its lower end to a clevis on theblock 152 by a pin 158. The upper end of the arm is formed as a clevis160, and below the clevis has an integral, forward facing hammer block162, and therebelow, a forward facing cam follower 164. A plunger 166has a forward end pivotally mounted to the clevis by a pin 168, anintermediate collar 170, and an aft spindle 172. The aft end of thespindle rides in a diametral bore through a dowel 174 which is mountedin a lateral bore through a toggle bracket 176. The bracket has an aftclevis 178 pivotally mounted to the rod 146 by a pin 180, and a forwardclevis 182 mounted to the rod 146 by a pin 184. A compression spring 186is mounted on the spindle 172 between the collar and the bracket 176.The cam follower 164 rides on each of the cam ramps 114 to compress thespring 186 which is preloaded. The hammer assembly may be safed byextracting the pin 184 and swinging the toggle bracket 176 aft about thepin 180, to preclude any effective compression of the spring 174. Thehammer assembly may be armed and the spring 174 preloaded by swingingthe toggle bracket 176 forward and inserting the pin 184.

Each of the eight chambers 190 is formed as a tube having a pair oflongitudinally distal lugs 192 at one end and a pair of longitudinallyset back lugs 194 at the other end. The tubes are alternated end for endso that a lug 192 can overlap the next adjacent lug 194. Each lug has alongitudinal bore therethrough which receives a respective bushing, andadjacent lugs are linked by respective rods 196 each having a forwardroller 198 and an aft roller 26%}. A forward ring seal 202 is disposedin a recess 204 inthe forward end of the chamber and an aft ring seal206 is disposed in a recess 208 in the aft end of the chamber.

A forward cam plate 210 and an aft cam plate 212 are respectivelydisposed in a forward channel 214 and an aft channel 216 in the rearhousing, and are pinned in place. When the rotor is in place, the platesmust be unpinned from the rear housing before the housing can beremoved. The rear cam plate may be removed once the rear housing hasbeen detached. The front cam plate can be removed after the chambers 190have been removed. Two holes 218 in the upper portion of the rear camplate can be utilized for longitudinal withdrawal of any two adjacentrods 196 to permit the removal of the contained chamber, as forinspection of the chamber seals. The cam plates 21%, 212 have respectivecam tracks 220, 222 for respectively supporting the rollers 198, 200 forguiding the chambers 190 through the transition between the upper andlower portion of the loop, and around the lower portion. in the upperportion of the loop each chamber is disposed in and carried by arespective recess 100 in the rotor. Each chamber has two lines ofcontact 201 with the recess wall profile. This assists in the accuratealignment of the chamber and the respective barrel bore, and provides aclearance space at the bottom of the recess for the accumulation offoreign matter which might otherwise disturb the chamber position.

As shown in FIGS. 6 and 10, the barrels and the rotor 72 revolve about alongitudinal axis A. The chain of chambers 190 is carried around by therotor 72 serving as a six tooth sprocket, and is guided around a virtualsix tooth sprocket having a longitudinal axis B. The transverse distancebetween the axes A and B is equal to the transverse distance between theaxes of adjacent shafts 196, i.e., the link length. The transversedistance between the axes A and B is also equal to the transversedistance between the axis A and the axis of the shaft 196 of anychamberengaged with the rotor 72, and is also equal to the transversedistance between the axis 8 and axis of the shaft 196 of any chambereffectively carried around the virtual sprocket. The virtual sprocket,as shown, can not be realized since it would then overlap in volume thereal sprocket 72. However, the effect of the sprocket is provided by thecam tracks 220, 222 which guide the rollers on the shafts, and, thereby,the chambers through the cusp transitions between the sprockets andaround the virtual sprocket. No cam tracks are provided around the uppersemicircle 72 as the rollers 198, 200 ride on the sprocket. It may benoted that by locating the axes of the shafts 196 external to the rotor,relatively deep recesses 100, with relatively thick distal rib sectionstherebetween, can be provided. Should it be desired to realize thevirtual sprocket and/or to increase the number of chambers in the chain,as shown in FIG. 11, it is merely necessary to make the transversedistance between the axes of the rotors a multiple of the link length,and to add one additional cam track cusp for each additional linklength. For example, ten chambers can be accomodated around and betweentwo rotors whose rotors axes are spaced apart by two link lengths, andprovided with cam tracks having two cusps per side. The use of the cuspsis necessary to maintain'the rotor inter axis spacing constant duringmovement of the chain of chambers around the rotors.

The forward and aft cam plates also serve to retain the chamber seals inthe respective chambers during the feed cycle when these chambers are inthe lower portion of the loop. The forward cam plate also serves as afixed stop and has an elastomeric shock absorbing surface adjacent theend of an ejection slot 224 in the lower portion of this plate to haltnewly chambered rounds flush with the forward end of the respectivechamber.

Rounds handed into the gun by the feeder assembly 50.are chambered by arotary feed tray 230 and a stationary ram cam 232. A back plate 234 isfixed to the aft end of the aft housing. A longitudinal support rod 236is fixed to the back plate. The rotary feed tray 230 has sixlongitudinal recesses 235, each for receiving a cartridge, and isjournaled on the rod 136 by a forward bearing 238 and an aft bearing240. An annular spur gear 242 is coaxial with and fixed to the aft endof the tray 230. A shaft 244 is joumaled to the aft housing, has aforward spur gear 246 fixed thereto and meshed with and driven by therotor spur gear 112, and has an aft spur gear 248 fixed thereto andmeshed with and driving the tray gear 242 through an aperture in thehousing. A spur gear 250 of the feeder assembly clutch 50 is also meshedwith and is driven by the tray gear 242. The stationary ram cam 232 is alateral section of a type and has a cycloidal cam slot 252 having aforwardly sloping shoulder 254 which extends around the complete ram areat the bottom of the housing and slopes forward one full round length.

Gun action may be considered to start with a cartridge in the feedersprocket 58. The feed tray 230 rotates in synchronization with the loopof chambers 190 and the rotor 72. Depending upon the type of'feed systemused, the cartridge will have been picked up by the sprocket from aconveyor, or handed in directly from the exit unit of a storage drum. Asthe feeder sprocket rotates, the cartridge is cammed centrifugally bythe side guides until its pitch velocity matches that of the rotary feedtray. Hand off into a recess of the rotary feed tray is thusaccomplished without any abrupt change in velocity. After hand off, thecartridge is controlled by the feed tray. Lateral movement of thecartridge is precluded by the contour of the respective recess and theadjacent interior wall of the stationary ram cam 252. The cartridge iscarried in coaxial alignment with an empty chamber and is free to moveforward longitudinally. Forward ramming begins after the cartridge hasbeen fully captured in the rotary feed tray. As the cartridge is carriedaround by the rotary feed tray it is also slid along in the stationaryram cam slot 252, whose shoulder 254 abuts the aft end of the cartridgeand cams the cartridge longitudinally forward into the chamber. In FIG.3, cartridge 256 is shown partially chambered. Once chambered, thecartridge remains chambered as the respective chamber moves into itsrespective rotor recess and is sealed between its respective barrel 78and firing pin head portion 128. The cycloidal shape of the ram camaccelerates the cartridge uniformly, and allows it to decelerate as muchas possible under the effect of friction before striking the stop. Asthe chamber passes the firing position the cam follower 164 rides off arespective cam ramp surface 114 and the released compression spring 186drives the hammer arm 156 forward to impact the firing pin spindle 134to fire the cartridge. Since the cartridge is caseless and consumable,the chamber is empty after firing and is ready to receive a freshcartridge. To clear the gun at the end of a burst, the clutch 56 isdisengaged to halt the feeder assembly drive shaft while the rotorassembly continues to rotate and fire all chambered cartridges. The guncomes to a full stop with all of its chambers empty.

The gun is designed to utilize a telescoped cartridge having acylindrical shape without any step or taper. Thus a fresh cartridgeincoming aft will displace a misfired cartridge presently in a chamberand force it out forward. No provision need be made for separableextraction of misfired cartridges, and this combining of the feeding andextracting processes greatly simplifies the gun. Room is left ahead ofthe loading area for a misfired cartridge to clear the housing. As amisfire begins to be ejected from its chamber, it is captured andcontrolled by a gear driven ejector assembly forward of the chamber, asshown in FIGS. 3, 7, 8, and 9.

The misfire ejector assembly comprises a worm 260 fixed on a shaft 262which is journaled to and between the bearing block 26 and the rib 21,and has a mitre gear 264 fixed thereto. A power shaft 266 is journaledto the housing and at its aft end is coupled to a power source, notshown, such as a hydraulic motor. A mitre gear 268 is fixed to theforward end of the shaft and meshed with the worm mitre gear 264. A spurgear 270 is also fixed to the shaft 266 and is meshed with a spur gear272 fixed on the shaft 244. A pressure roller 274 is mounted to thehousing by a spring 276 at an angle to the worm. The worm is providedwith a friction surface composed of wire studs embedded in the wormsurface and fixed with epoxy.

As the eight chambers rotate around the lower portion of the loop on asix chamber circle past the ejection slot 224 they maintain a spacing of60 between adjacent chambers. The worm lead is also 60 of profilerotation for one revolution of the worm. Thus the-concavity 276 in theworm provides a shape which laterally mates with the cylindrical shapeof the cartridge, so that the cartridge remains longitudinally alignedwith the bore of the chamber as the chamber progresses along theejection slot. For each revolution of the rotor the worm is geared torotate six times, allowing the concavity shape to follow all sixchambers.

As a chamber containing a misfired cartridge progresses along theejection slot, the fresh cartridge then being chambered by the ram campushes the misfired cartridge longitudinally forward, from the chamberbore, through the ejection slot, as shown in FIG. 8, into the concavity276 of the worm, under the spring loaded roller 274. The worm acts as anendless conveyor which supports, cradles and longitudinally stabilizesthe cartridge as it is ejected. In addition, the relatively highperipheral speed of the worm accelerates the cartridge out of thechamber and creates a gap between the aft end of the misfired cartridgeand the fresh cartridge being chambered. The ejection slot terminates,and the wall of the forward cam plate 210 is accomodated in this gap.The aft surface of the forward cam plate serves to stop the freshcartridge when it is fully chambered. The spring loaded roller ensuresengagement between the misfired cartridge and the worm during gun lowspeed or hand cycling. Centrifugal force serves this function atrelatively higher gun speeds.

To insure clearing of all chambers at the end of a burst of firing,after the declutching operation has occurred,an air blast is provided.If a misfire should occur in the last eight rounds chambered prior todeclutching, the air blast must serve in lieu of an incoming round todisplace the misfire. An air fitting 280 is fitted into a longitudinalblind bore 282 in the support rod 236 which communicates with a radialbore 284 directed downwardly. Six air tubes 286 are disposed in the feedtray 230, each respectively aligned with a recess 235. The air tube forthe lowermost recess, which is the chamber-eject position, is incommunication with the bore 282. When the burst of firing is to beended, the supply of cartridges to the feeder assembly 50 isdiscontinued and a supply of air is delivered to the fitting 280. As thefeed tray rotates, a blast of air is delivered successively through eachair tube to the respective chambers to blast out any misfired cartridgecontained therein.

In a revolving battery gun it is desirable that the ammunitionpropellant ignite at the twelve oclock position to preclude or at leastminimize, lateral torque on the gun mounts. In ammunition having a stabprimer there is a significant delay between the time of firing pinimpact and propellant ignition. Thus it is necessary to finely adjustthe searing of the hammer to preceed the chamber arriving at the 12oclock position by the delay interval. This adjustment is accomplishedby adjusting the effective length of the rod 154, by means of the twonuts 155, to swing the hammer assembly on its pivot rod 146.

While there has been shown and described a preferred embodiment of thisinvention, it will be appreciated that theinvention may be embodiedotherwise than as herein specifically illustrated or described, and thatcertain changes in the form and arrangement of parts and in the specificmanner of practicing the invention may be made without departing fromthe underlying idea or principles of this invention within the scope ofthe appended claims.

What is claimed is:

1. A machine gun comprising:

a housing;

a first rotor journaled for rotation in said housing about a first axis;j a first plurality of barrels fixed in said first rotor in an annularrow;

a first plurality of individual, spaced apart recesses,

equal in number to said first plurality of barrels and formed in theperiphery of said first rotor in an annular row, each. recesslongitudinally aligned with a respective barrel and havinglongitudinally spaced apart forward and aft ends, said forward endopening on said respective barrel and said aft end closed by an aftportion of said rotor;

second rotor equivalent means having a second axis spaced from andparallel to said first axis; and

a second plurality of chambers, greater in number than said firstplurality of barrels, linked together in an endless chain, guided formovement around said first rotor with each said chamber periodicallyoccupying and longitudinally fore and aft and centripetally supported bya respective recess, and guided for movement around said second rotorequivalent means;

each of said chambers being linked to and between its next adjacentchambers by a pivotal connection having a cam follower,

the transverse distance between the axes of immediately adjacent pivotalconnections defining the link length of said chain;

the transverse distance between said first and second axes being equalto a multiple of said link length; and

the transverse distance between said first axis and each of therespective adjacent pivotal connection axes, and between said secondaxis and each of the respective adjacent pivotal connection axes beingequal to said link length.

2. A machine gun according to claim 1 further including:

cam track means for receiving said cam followers and guiding saidrespective chambers between said first rotor and said second rotorequivalent means;

said cam track means including:

4. A machine gun according to claim 2 wherein: said transverse distancebetween said first and 3. A machine gun according to claim 2 wherein:said transverse distance between said first and second axes is equal toone multiple of said link length;

said firs rotor is real; said second rotor equivalent means is acontinuation each said portion of said cam track means has one cusprespectively.

second axes is equal to two multiples of said link length;

said first rotor is real; said second rotor equivalent means is a realrotor journaled in said housing for rotation about said second axis andhas a second plurality of recesses, equal in number to said firstplurality of recesses, formed in the periphery thereof, and

each said portions of said cam track means has two cusps respectively.

5. A gun according to claim 1 wherein: as each chamber enters arespective recess in said first rotor it pivots relative to said recessabout its leading pivotal connection, the cam follower of said leadingpivotal connection being disposed extemal to the peripheral surface ofsaid first rotor.

6. A machine gun comprising: a housing; a first rotor journaled forrotation in said housing about a first axis;

a first plurality of barrels fixed in said first rotor in an annularrow;

a first plurality of individual, spaced apart recesses,

end closed by an aft portion of said rotor;

second rotor equivalent means having a second axis spaced from andparallel to said first axis;

a second plurality of chambers, each for repeatedly receiving rounds ofammunition, greater in number than said first plurality of barrels,linked together in an endless chain, guided for movement around saidfirst rotor with each said chamber periodically occupying andlongitudinally fore and aft and centripetally supported by a respectiverecess, and guided for movement around said second rotor equivalent r nans; and feeder means for sequentialy inserting a round of ammunition ineach of said chambers in said chain as it passes around said secondrotor equivalent means.

7. A gun according to claim 6 wherein:

the longitudinal axis of each of said recesses in said first rotor isspaced from and parallel to the longitudinal axis of each of saidchambers when disposed therein, whereby the longitudinal outer wallsurface of said chamber abuts the longitudinal inner wall surface of therespective recess along two lines of contact, with a gap between thebottom of said recess surface and the adjacent chamber surface.

8. A gun according to claim 6 wherein:

said first rotor has a like first plurality of firing pin assemblies,equal in number to said first plurality of barrels, said firing pinassemblies being disposed in a transverse annular row through the aftend of said rotor, each pin assembly being coaxial with a respectivebarrel:

each pin having a plunger extending aft of said rotor and having anenlargement thereon; and

a cam fixed on said housing and adapted to engage each plungerenlargement in sequence, after a respective chamber has left therespective recess, to positively reset the respective plunger aft.

9. A gun according to claim 6 further including:

a like first plurality of firing pin assemblies, equal in number to saidfirst plurality of barrels, said firing pin assemblies being disposed ina transverse annular row through the aft end of said rotor, each pinassembly being coaxial with a respective barrel, and each pin having aplunger extending aft of said rotor;

an ignition station defined as a point along the path of travel of saidchambers while recessed in said first rotor and aligned with arespective barrel;

means for actuating each plunger in sequence as it approaches theignition station;

means for supporting said actuating means and for adjusting its spacingfrom said ignition station.

1. A machine gun comprising: a housing; a first rotor journaled forrotation in said housing about a first axis; a first plurality ofbarrels fixed in said first rotor in an annular row; a first pluralityof individual, spaced apart recesses, equal in number to said firstplurality of barrels and formed in the periphery of said first rotor inan annular row, each recess longitudinally aligned with a respectivebarrel and having longitudinally spaced apart forward and aft ends, saidforward end opening on said respective barrel and said aft end closed byan aft portion of said rotor; second rotor equivalent means having asecond axis spaced from and parallel to said first axis; and a secondplurality of chambers, greater in number than said first plurality ofbarrels, linked together in an endless chain, guided for movement aroundsaid first rotor with each said chamber periodically occupying andlongitudinally fore and aft and centripetally supported by a respectiverecess, and guided for movement around said second rotor equivalentmeans; each of said chambers being linked to and between its nextadjacent chambers by a pivotal connection having a cam follower, thetransverse distance between the axes of immediately adjacent pivotalconnections defining the link length of said chain; the transversedistance between said first and second axes being equal to a multiple ofsaid link length; and the transverse distance between said first axisand each of the respective adjacent pivotal connection axes, and betweensaid second axis and each of the respective adjacent pivotal connectionaxes being equal to said link length.
 2. A machine gun according toclaim 1 further including: cam track means for receiving said camfollowers and guiding said respective chambers between said first rotorand said second rotor equivalent means; said cam track means including:a first portion for guiding said links between said first rotor and saidsecond rotor equivalent means, a second portion for guiding said linksbetween said second rotor equivalent means and said first rotor, andeach of said portions includes at least one cusp and an additional cuspfor each multiple over the first of said link length distance betweensaid first and second axes.
 3. A machine gun according to claim 2wherein: said transversE distance between said first and second axes isequal to one multiple of said link length; said firs rotor is real; saidsecond rotor equivalent means is a continuation of said cam track meansbetween and including said first and second portions of said cam trackmeans for guiding said cam followers and said respective chambers alonga path identical to that which would be provided by a real rotor; andeach said portion of said cam track means has one cusp respectively. 4.A machine gun according to claim 2 wherein: said transverse distancebetween said first and second axes is equal to two multiples of saidlink length; said first rotor is real; said second rotor equivalentmeans is a real rotor journaled in said housing for rotation about saidsecond axis and has a second plurality of recesses, equal in number tosaid first plurality of recesses, formed in the periphery thereof, andeach said portions of said cam track means has two cusps respectively.5. A gun according to claim 1 wherein: as each chamber enters arespective recess in said first rotor it pivots relative to said recessabout its leading pivotal connection, the cam follower of said leadingpivotal connection being disposed external to the peripheral surface ofsaid first rotor.
 6. A machine gun comprising: a housing; a first rotorjournaled for rotation in said housing about a first axis; a firstplurality of barrels fixed in said first rotor in an annular row; afirst plurality of individual, spaced apart recesses, equal in number tosaid first plurality of barrels and formed in the periphery of saidfirst rotor in an annular row, each recess longitudinally aligned with arespective barrel and having longitudinally spaced apart forward and aftends; said forward end opening on said respective barrel and said aftend closed by an aft portion of said rotor; second rotor equivalentmeans having a second axis spaced from and parallel to said first axis;a second plurality of chambers, each for repeatedly receiving rounds ofammunition, greater in number than said first plurality of barrels,linked together in an endless chain, guided for movement around saidfirst rotor with each said chamber periodically occupying andlongitudinally fore and aft and centripetally supported by a respectiverecess, and guided for movement around said second rotor equivalentmeans; and feeder means for sequentially inserting a round of ammunitionin each of said chambers in said chain as it passes around said secondrotor equivalent means.
 7. A gun according to claim 6 wherein: thelongitudinal axis of each of said recesses in said first rotor is spacedfrom and parallel to the longitudinal axis of each of said chambers whendisposed therein, whereby the longitudinal outer wall surface of saidchamber abuts the longitudinal inner wall surface of the respectiverecess along two lines of contact, with a gap between the bottom of saidrecess surface and the adjacent chamber surface.
 8. A gun according toclaim 6 wherein: said first rotor has a like first plurality of firingpin assemblies, equal in number to said first plurality of barrels, saidfiring pin assemblies being disposed in a transverse annular row throughthe aft end of said rotor, each pin assembly being coaxial with arespective barrel: each pin having a plunger extending aft of said rotorand having an enlargement thereon; and a cam fixed on said housing andadapted to engage each plunger enlargement in sequence, after arespective chamber has left the respective recess, to positively resetthe respective plunger aft.
 9. A gun according to claim 6 furtherincluding: a like first plurality of firing pin assemblies, equal innumber to said first plurality of barrels, said firing pin assembliesbeing disposed in a transverse annular row through the aft end of saidrotor, each pin assembly being coaxial with a respective barrel, andeach pin having a pluNger extending aft of said rotor; an ignitionstation defined as a point along the path of travel of said chamberswhile recessed in said first rotor and aligned with a respective barrel;means for actuating each plunger in sequence as it approaches theignition station; means for supporting said actuating means and foradjusting its spacing from said ignition station.